It is often desirable to separate a dilute phase particulate laden pneumatic stream from a primary conduit into branch streams. A dilute phase stream has a minimum of approximately 21/4 standard cubic feet of air per pound of solids and an air velocity of between approximately 3200 feet per minute and 6000 feet per minute depending upon the solids. When the stream is of the type commonly referred to as a dilute phase or stream flow, the velocity of the conveying gas theoretically is sufficiently high and the amount of particulate is sufficiently low and uniform so that under ideal conditions all of the solid flow takes place near the center of the conduit.
In actual practice, a dilute phase stream does not always have the particulate solids concentrated adjacent the longitudinal axis of the conduit, but rather it may be to one side of said axis. Hence, division of the stream often results in a disproportionate separation. The present invention is directed to a solution of the problem of dividing the particulate in a dilute phase stream in accordance with a predetermined ratio.